The invention relates to a method and a device for producing a three-dimensional component consisting of plural layers.
1. Field of the Invention
An LOM (Laminated Object Manufacturing) method has been developed for producing prototypes and small runs and also for rapid tool and component production; the technique depends on laminar building up of plural layers of material which have the body geometry of the body to be produced. In the production, the data of a CAD construction are accessed. These data are prepared for controlling corresponding equipment which is used in layer construction, and produce the respective geometry of the corresponding layer in order to form a three-dimensional component. The requirements on such a method are increased because of the requirement that thin layers with a thickness of, for example, 0.1-1.0 mm are to be processed to produce a component.
2. Description of Related Art
From U.S. Pat. No. 5,637,175 there is known an embodiment of a method for producing a laminar built up component, in which a layer of a plate-form material is fed to a processing station, in which numerous layers were first positioned and were connected together. The last layer fed is applied to these layers and welded to them. The geometry of the layer is brought about by a laser tool, whereby a region exists in the layer which is to be maintained for the component, and a further region which is to be removed as waste. In order to perform this work section, the laser is guided along the undesired regions in order to weaken or release the solder connection, so that the undesired regions can be removed.
From this publication there is furthermore known a process in which a first shape is first cut from a length of material, and is supplied by a conveyor belt to a second processing station. In this processing station, a stack with plural layers is positioned under pressure to the newly supplied layer. By raster-form scanning with a laser, a weakening of the solder layer is effected, so that the newly applied layer is soldered to the stack. At the same time, the undesired regions are cut by the laser, so that only the region for forming the three-dimensional component remains on the stack.
These methods have the disadvantage that, in order to remove the undesired regions, which are connected to the stack by a solder or weld connection, a high energy has to be applied by means of a laser in order to remove this solder or weld connection. The bordering regions are also affected by the high processing temperature, so that internal stresses are formed in the component formed by laminar construction. Furthermore, the high applied energy can also give rise to a partial release of the adjacent superposed layers. The quality of the component is thus impaired. In addition, there is a high processing cost, in which undesired regions, which are the first soldered or welded, have to be removed again by a further heating.
Furthermore, a process follows from this publication in which the layers to be built up are provided in a heated chamber. It is provided here that the temperature of the chamber is just below the melting point of the solder, in contrast to which a heating roller is provided for connecting the uppermost layer to the stack, supporting the soldering process. This method has the disadvantage that due to the high temperature, melting occurs of the solder layer lying directly beneath the two layer to be connected, resulting in a danger of relative displacement of the layers due to the heating roller rolling over them. Due to this, a precise construction of the component with high process reliability cannot be given.
In WO 99/02342, a method and a device for producing a component with a laminar construction from metal foils have furthermore been disclosed. In this method, a composite material is employed, in which the layer provided for the component is arranged on a carrier material. A low-melting solder layer is provided between the layer provided for the component. A higher-melting solder layer is applied to the side against the carrier material. This carrier material is fed to a first processing station. Here the contour in the layer is introduced, for example by means of a laser. In a following station, the composite material above the higher-melting solder layer is heated, and the baseplate carrying the stack is moved up and down. The layer is applied to the stack under pressure. By cooling of the high-melting solder, the layer to be applied remains on the stack. The low-melting solder still remains liquid, so that the newly applied layer is lifted from the carrier material.
This method requires the preparation of an expensive composite material and an exact positioning of the contour of the layer to be applied to the stack for producing the desired component geometry.